SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c8315352975b48087c2743c048e52c771ce8e49eaf5fc5432288a7da42559840' 
  AND token = 'Lno2juT+2R0hIRsQzqu08qvJ+3Tl+Ut3ATnD6EG8T7c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}